Post by doug3b on Jan 19, 2021 18:15:26 GMT -5
I was excited to try out the procedure of timing my engine without a timing light. The engine has pretty much always ran rich, as long as I can remember.
First off, a little about my setup. I have a 1963 CJ3B with the F-134 Hurricane. I have about 6500 miles on a total engine rebuild. Probably about that many miles on the rebuilt Carter carb as well. I rebuilt it myself using a Carter Zip Kit in 2011. This past year, I put a Pertronix ignition in it. Disappointed in the results; $130 later and I noticed no difference over points. My problem of running rich long outdates the Pertronix install. Black plugs, a sooty exhaust pipe, and exhaust that smells like straight gasoline. I've tried to tune it multiple times, using procedures in both the service manual, and instructions from the old CJ3B Bulletin Board. I can get it to where the engine just purrs, but man does she run rich.
So, I tried the timing procedure today. Things started off well. Even though the engine was purring before, I bottomed out the idle mix screw then turned out 2 turns. I also adjusted the idle adjust screw as instructed - this caused the engine to "idle" at about 1400-1500 RPMs.
Engine was up to operating temperature.
I plugged my vacuum gauge into the port below the carburetor, but had to disconnect my PCV valve to do so. Not sure if that will skew readings or not.
With that, I was able to achieve 18-19 in Hg. Couldn't get anymore than that.
I backed it off 100 RPMs and at this point, I was "idling" at about 1400 RPM.
I tightened down the dizzy.
Here is where I really noticed things going down hill.
Adjusting the idle stop screw had pretty much no impact on the vacuum reading. I tried both ways, and vacuum started to drop either way I adjusted it.
So I said: Well, maybe that's just her sweet spot and moved on to the next step.
Adjusting my idle mix had no effect what so ever on the RPM. I had it bottomed out and she was humming right along same as she did when the idle mix was two turns out.
I have a feeling I'll be pulling apart my carburetor.
Here is a link to the photos I took during the carb rebuild. I believe I set the float to 5/16". Other than that, I don't remember what I did in there. Totally willing to pull it apart if there are questions
Link to Carb Rebuild (I hope that works)
Thank you so much for any help!
Doug
First off, a little about my setup. I have a 1963 CJ3B with the F-134 Hurricane. I have about 6500 miles on a total engine rebuild. Probably about that many miles on the rebuilt Carter carb as well. I rebuilt it myself using a Carter Zip Kit in 2011. This past year, I put a Pertronix ignition in it. Disappointed in the results; $130 later and I noticed no difference over points. My problem of running rich long outdates the Pertronix install. Black plugs, a sooty exhaust pipe, and exhaust that smells like straight gasoline. I've tried to tune it multiple times, using procedures in both the service manual, and instructions from the old CJ3B Bulletin Board. I can get it to where the engine just purrs, but man does she run rich.
So, I tried the timing procedure today. Things started off well. Even though the engine was purring before, I bottomed out the idle mix screw then turned out 2 turns. I also adjusted the idle adjust screw as instructed - this caused the engine to "idle" at about 1400-1500 RPMs.
Engine was up to operating temperature.
I plugged my vacuum gauge into the port below the carburetor, but had to disconnect my PCV valve to do so. Not sure if that will skew readings or not.
With that, I was able to achieve 18-19 in Hg. Couldn't get anymore than that.
I backed it off 100 RPMs and at this point, I was "idling" at about 1400 RPM.
I tightened down the dizzy.
Here is where I really noticed things going down hill.
Adjusting the idle stop screw had pretty much no impact on the vacuum reading. I tried both ways, and vacuum started to drop either way I adjusted it.
So I said: Well, maybe that's just her sweet spot and moved on to the next step.
Adjusting my idle mix had no effect what so ever on the RPM. I had it bottomed out and she was humming right along same as she did when the idle mix was two turns out.
I have a feeling I'll be pulling apart my carburetor.
Here is a link to the photos I took during the carb rebuild. I believe I set the float to 5/16". Other than that, I don't remember what I did in there. Totally willing to pull it apart if there are questions
Link to Carb Rebuild (I hope that works)
Thank you so much for any help!
Doug
